import java.util.Scanner;

public class java18 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("输入第一个数：");
        double x = scanner.nextInt();
        System.out.println("输入第二个数：");
        double y = scanner.nextInt();
        scanner.nextLine();
        String s=scanner.nextLine();
        switch (s)
        {
            case "+":
                jiafa(x,y);
                break;
            case "-":
                jianfa(x,y);
                break;
            case "*":
                chengfa(x,y);
                break;
            case "/":
                chufa(x,y);
                break;
            default:
                System.out.println("输入错误");
        }
    }
    public static void jiafa(double a,double b)
    {
        double c=a+b;
        System.out.println(+c);
    }
    public static void jianfa(double a,double b)
    {
        double c=a-b;
        System.out.println(+c);
    }
    public static void chengfa(double a,double b)
    {
        double c=a*b;
        System.out.println(+c);
    }
    public static void chufa(double a,double b)
    {
        double c=a/b;
        System.out.println(+c);
    }
}
